Shock eliminator



Oct. 20, 1931. E. SLADE 1,328,549

SHOCK ELIMINATOR Filed April 14, 192 2 Sheets-Sheet l IN VEN TOR.

, E. SLADE SHOCK ELIMINATOR Oct. 20, 1931 Filed April 14, 192' 2 Sheets-Sheet 2 UNITS In Item oFikncnousar-Su.)

5P )UND 1N JIM-FE Gina-Ive JNV NTOR.

A RNEYS.

Patented Qct. 20, 1931 Enwnnn SLADE, ornnw YORK, n. 71., Ass

TION, OF TROY, YORK, A GORPORATION OF DELAWARE I snockj 'nnraimiron;

A plication filed A rufi i,

-oi: vehicles. In describing myinvention,

however, I will refer specifically to its use on vehicles and more particularlytomotor driven vehicles. '1 I r The object ofmy invention is to provide a device of that type wherein the shockis eliminated or prevented by agradual braking action which is self-adjusting to the degree, speed and power of shock producing movements, rather-than by a direct braking, absorbing or snubbing action as is the case in devices of this character heretofore employed for overcoming the effects of rapid and abrupt movements imparted to movable bodies in passing overor striking obstructions, ruts, or other impedimentswhich may suddenly impede or retard the normal or bodies. v i To accomplish the objectof-m'y invention I: employ a device which operates on theprinciple of a friction brake, and is so arranged that it will function with a lower or'higher coefficient of friction according to the speed, degree and power of the shock producing movements; In other words, when the shock producing'movements are slow and tending to produce slight shocks, the action ofmy device is such that the brakingelement takes hold more slowly, that is, for a' given degree 5 of movement, therelative movement ofthe brake inembers'upon eachother is'slower, with slight changes in springpressnre, and hence the coeflicient of friction will be-p'ro portionately lower. On the other hand, whenthe shock producing movement is very shock resultin from the ra id andabruat- 1927; Serial nbfisa'z i xenon, T0 MARSHALL ASBESTOS conroaavehicle traveling at high speed over a narrow deep rut, thenthe brakingelement will be caused to function with corresponding rapidity, greater degree of movement of the drum and consequent increased spring tension, and therefore with a correspondingly higher coefiicient of friction, Thus I employ a frictional braking device which is self-adjusting to the degree, speed and power of the shock producingmovement.

A further object of my invention is to produce a device of this character which will be subject to the minimum of wear in operation and in which theproper fui'ictioning will not "vary materially with'the wear of co-acting parts or friction'elements; also to produce such a device iniwhich there will be no structurally loose parts, or parts becoming loose through wear, and causing noise when in op 'eration; also-to produce a device in which a simple take-up will readjust the device -tocompensate forwear; also to produce a device whichwillbe practically weather and dust proof; also to produce a device whose parts are readilyassembled, and one which may be readily mounted in operative position, adjusted or dismounted; and finally to produce such a device having as few parts as possible and of such form as to-be produced by the most 'eflicient manufacturing methods. smooth sllding or rolling inotlon of such" My improved shock eliminator consists essentiallyof a brake vheel rigidly mounted upon a supporting meinbena floating brake member or drum surrounding the brakewheel and flexibly or resiliently connected to or carried by said supporting member, as by a fiat' spiral spring, and flexible pulling means connected to the drum for imparting rotary motion thereto in one direction. The supporting member, in practice, is rigidly 'mountedupon a part or member of an object, apparatus, machine, vehicle or other body, and the flexible pulling means, which may be a'wire cable, chain or strap, is connected to another part ormemberof the object, apparatus, machine, vehicle or other body subject 'to'sliock under operating conditions, and this flexible connection is essentially taut, under initial te'n'sion, and adj ustably secured either size or make of vehicle.

is anchored, at either end. The diameter of the brake wheel is slightly less than that of the inner surface of the drum so that the drum, due to the pulling action of the cable, will be in frictional engagement with the brake Wheel only over a small arc, and as the drum is rotated in one direction by the pull .of the cable (which increases the spring tension) or in the opposite direction by the recoil of the spring, the drum in rotating on the brake wheel will have a sliding action with a varying degree of friction.

One of the advantages in having a braking action which is self-adjusting to the degree,

speed and power of the shock producing movement is that one size or type shock eliminator according to my invention Wlll serve for any one kind of use. vThat is to say, in shock eliminators for motor vehicles, for instance, only one size or type will be necessary to meet the requirements for any This is due to the self-adjusting braking or retarding action of my device, whereby the coeflicient of friction is variable directly with the degree, speed and power of the shock producing movement. A further feature of my improved shock eliminator'is that the flexible pulling member such as a wire cable, is wound on the exterior of the floating drum which also serves as the casing of the device, thereby avoiding the use of open casings for admitting the strap to a winding drum as commonly employed in shock absorbers as heretofore made, and thus I am enabled to utilize a closed floating drum and protect the friction elements from the action'of weather, dust, etc. Furthermore, by applying the pulling member for the floating drum on the exterior of the casing a much wider latitude for adjustment is obtained to meet the varying requirements of spring tension in different makes or weights of motor vehicles. A

further advantage obtained by placing the pulling element on the exterior of the casing is that any length of cable may be employed to meet varying structural conditions in different makes or types of motor vehicles. The functioning of these elements and the opera-- tion of the device will be described more in detail hereinafter.

My invention is illustrated in the accompanying drawings in which, Figures 1 and 2 are elevations of opposite sides of the device; Figure 3 an edge view looking at the right of Figure 1; Figure 4 an enlarged vertical less qualities.

section through Figure 1 looking in the direction of the arrows and illustrating the position of the parts when not under tension; Figures 5 and 6 vertical sections through Figure 3 looking in the direction of the arrows and on the same scale as Figure 4,

illustrating two different positions of the parts with the spring under tension; Figure 5 showing the position of the parts when the spring is under its initial tension only and the brake members in the normal position, and Figure 6 showing a position of the brake members when a shock producing movement imparted to a vehicle body takes place and the slack in the pulling cable is taken up by the brake drum rotating counter clock-wise through the recoil of the spring; and Figure 7 is a chart showing approximate coeflicient of friction curves for rapid and slow shock producing movements. i

Referring to the drawings, and more particularly to Figure 4, the supporting member 1 is represented as a spindle having a squared end 2 seated in a square hole in bracket 3. This bracket in practice will be of a shape adapted for clamping to the chassis of a .motor vehicle. The brake-wheel which may be in the form of a pressed steel circular box has a web 4, flange 5 and asbestos or other friction material 6 wrapped entirely around the outer periphery of the flange and secured thereto in any suitable manner. The center of the web 4 is perforated to fit closely on spindle land is riveted or otherwise rigidly or permanently secured to a flange which may be formed on the spindle or on a hub fitting on the spindle, but in either case fixed on the spindle, so that the brake-wheel will remain stationary upon the supporting member. The purpose in making the brake-wheel of box-like form is to house the flat spiral spring 7. This spring at its inner end has a short sharp bend for engaging a slot 8 in the spindle 1 or brake wheel hub, and the outer end is formed into a hook 9. This hook engages a pin 10 projecting from the web of the brake-drum 11. The brake-drum is a pressed steel box having a tight fitting cover 12 with central perforations for spindle 1 of such diameter as to permit ample movement of the drum perpendicular to the spindle. The apertures in the drum are closed by heavy stiff fibre washers 13 on the exterior of the drum and 14 on the interior, all of which fit closely on spindle 1. These washers may be of'any other material, but preferably should have friction reducing, non-rusting and noise- The drum is held in spaced relation to the brake-wheel by the interior washers 14, on the left hand side by reason of the washer being located between web 4 and cover 12 and on the right hand side by reason of the washer being located between the brake-wheel hub and the web of drum 11. The frictional contact between the brakewheel, drum-web and cover adjusted by meansof spring disks 15and nut16 on the outer end of the supporting? spindle. From the foregoing description. and by reference to F igure lit will be observed that the brakedrum casing is held in fixed lateral relation to'thebralie-wheel but is free to move radially in all directions in accordance with the combined force of spring '7 and the pull of cable 17,. which. isnot shown in Figure 4. The pulling member, cable '17, is provided with an anchor 18 for detachably engaging a bifurcated hoolr19 riveted or otherwise secured to the drum 11 and the other end of the cable is provided with a screw threaded ferrule and nut 19 for adjustably securing the cable to a shackle or other plate 20, Figure 5, uhereby connection is made, in the case of a motor vehicle, with a shackle on a spring or axle.

Referring now to Figure 5 it will be observed that the brake-drum has been rotated 1.80 degreesv from the position shown in Figure l, or from the position shown by the .dotted circle which indicates the position of pin 1.0 in Figure 4;, and which position as above stated is the position of the brakedrum before placing the spring 7 under initial tension. The. normal initial tension of the spring may be set according to the weight of the vehicle and. this willbe approximately a" tension due to a rotation of the drum 180 degrees in adjusting the cable; To increase the tension slightly beyond that indicated in Figure 5.,the cable may be further taken up by adjusting nut 19, which will rotate the drum cloclnwisca correspondin distance.

If a reater increase is desired 7 refer to obtain the adjustment by resetting the supporting spindle 1 in the bracketby removing the nut,.w thdrawmg the spindle from the bracket, 18111881tl1lg thespindle after giving it a quarter turn, counter clock-wise, and then locking'the' spindle in position. This resetting. would carrythe hooked end 9 of spring? and pin IO-backward to a pointindicated by the dotted circle 10a and then when the cable is drawn downward to engage its end with the shackle-plate the hookedend of the spring and pin 10 would again be at the point shown in Figure 5 with an initial tension due to a turn of 2.70 degrees. Then if desired the tension may be further modified, to increase or decrease same, by adjustment at the shackleplate 20. This method of adjustment by resetting the spindle 1 may also be employed to compensate for wear of the asbestos brake-wheel facing.

It will be observed that in Figure 5 the line of'contact between the brake-wheel and speed and power of a shock and the body upon which. the brake-wheel and drum are, mounted moves downward, cable 171beco-mes slack and drum 11 is free to rotate toward the positionindicated in- F igure 6 under the pull of'spring 7. During such movement of the vehicle body the pull of spring ,7' as it recoils will. rotate. the brakedrum counter clock-wise with a combined rolling and slidingactio-n on the'brake-wheel until the cable becomes taut and holds the drum against further rotation,and thus the line of contactbetween theqdrum and brake wheel will be transferredto an are lying approximately between hook 18 and pin 10 as indicated in Figure .6. As the vehicle body moves upward due to the reboundof its springs; the upward movement of the brakewheel and drum produces a pull on the cable, equivalent to pulling the cable through the shackle 20, and this pull rewinds spring 7 by rotating drum 11 in a clock-wise direction from the position ofFigure 6 toward the position'of Figure 5.v This pull of thecable causes a rollingand sliding efiect of the drum on the brake-wheel with gradually increasing friction as the tension of thespring is 1ncreased resultlngln a gradual slowing up of the upward movement of the vehicle body and thereby. causingthe vehicle springsto' act in a normal mannerand eliminating the shock which would otherwise result. Thus itwill be seen that the action of my shock eliminator is self-adjusting and that the coeflicient of friction is at all times controlled by and variable. according to the degree, producing move ment. 1 1 l In Figure 7 I show a chart with two curves which represent the variations in the coefli cie-nt of friction inthe operation of my device under rapid and slow shock producing movements. In this chart the horizontal lines represent the pull of the cable in pounds and the vertical lines represent the speed ofv rebound in'inches'. From this chart it will be observed that upon a rapid rebound the coefficient of friction increases gradually with the pull, speed and degree of rebound, and

that with a slow rebound the rise in the coefficient of friction is much slower.

From .the foregoing it willbe noted that my improved shock eliminator embodies all the objects of my'invention, especi ally in that it is self-adjusting to varying shock producingmovements to effect gradual checking; the braking elements are housed within a closed casing; the moving parts are noiseless since all are subject tospring pressure there by insuring against possible rattling due to wear in operation;'the entire-assembly of parts is held by one nut which is locked in position; with the exception 'ofthe spindle, pin and nuts theparts are all punch and press work; furthermore;there,is. no'point at which a sudden jerk on the cable is not met with an elastic resistance; and locking or seizing of the brake'elements is impossible as the resistance to shock is a sliding coefficient of friction between the drum and brake-wheel.

What I claim is:

l. A shock eliminator comprising a supporting member, a pulling member, and a friction member intermediate the supporting and pulling members, said friction member comprising a fixed drum and a rotary drum, one working within the other, the rotary drum having a diameter permitting radial movement relative to the fixed drum, and a coiled spring connected between said drums for producing relative angular movement in a direction opposite to that of the pulling member, whereby the angular movements resulting from the pull of the spring in one direction and the'pull' of the pulling member in the opposite direction will produce a change in radial position of the rotary drum relative to the fixed drum and a consequent change in the coefficient of friction at either end of the movement, and a gradually varying coefiicient during the rotation of the drum due to the gradually changing radial position thereof.

2. A shock eliminator comprising a supporting member, a friction member having a fixed drum and a rotary drum, one working within the other and the rotary drum having a diameter permitting engagement with the fixed drum both by rolling and slipping contact, a pulling member connected with the rotary drum, and a coiled spring connected between said drums for producing relative rotary movement in a direction opposite to that imparted by the pulling member, whereby the rotary movements resulting from the pull of the spring in one direction and the degree of movement imparted by the pulling member in the opposite direction will produce changes in the radial position of the rotary drum relative to the fixed drum with consequent changes in coefiicient of friction at either end of the movement, and a gradually varying coefficient during the rolling and slipping of the rotary drum due to the gradually changing radial position relative to the fixed drum. 7

3. A shock eliminator comprising a supporting member, a friction member having a fixed drum, mounted on said supporting member, and a rotary drum surrounding the fixed drum, the rotary drum having a diameter permitting engagement with the fixed drum both by rolling and slipping contact, a pulling member engagingthe outer periphcry of the rotary drum, and a coiled spring within and connected betweensaid drums for imparting angular movement to the rotary drum in a. direction opposite to that imparted by the pulling member, whereby the rotary movements resulting from the pull of the spring in one direction and the degree of movement imparted by the pulling 1 ember in the opposite direction will produce changes in the radial position of the rotary drum relative to the fixed drum with consequent changes in coefficient of friction at either end of'the movement, and a gradually varying coefficient during the rolling and slipping of the rotary drum due to the gradually changing radial position relative to the fixed drum.

4. A shock eliminator having in combination a stationary supporting member, abrakewheel having a fixed position thereon, a spiral spring within said wheel having its inner end connected to said support, a brakedrum surrounding said wheel and to which the other end of said spring is connected, said drum being mounted upon said support so as to be capable of rotary and radial movement with respect to said wheel, said drum being of box-like form with a tight fitting cover enclosing said wheel and spring, and a flexible pulling member wound upon the periphery of said drum and having one end detachably connected thereto and the other end adapted for adjustable connection to a relatively stationary element.

5. A shock eliminator having in combination a stationary supporting member, a brakewheel having a fixed position thereon, and having a wide circumferential flange faced with friction material, a spiral spring within said wheel having its inner end connected to said support, a brake-drum surrounding said wheel and to which the other end of said spring is connected, said drum being mounted upon said support so as to be capable of rotary and radial movement with respect to said wheel, said drum being of box-like form with a tight fitting cover enclosing said wheel and spring, and a flexible pulling member wound upon the periphery of said drum and having one end detachably connected thereioo to and the other end adapted for adjustable connection to a relatively stationary element.

6. A shock eliminator having in combination a supporting spindle rigidly mounted upon a bracket, a brake-wheel of box-like form mounted upon said spindle and rigidly secured thereto, a spiral spring within said wheel having its inner end connected to said spindle, a brake drumv of box-like form having a tight fitting cover enclosing said brakewheel and spring, a pin projecting from one side of said drum for engaging the outer end of said spring, central perforations in the walls of said drum through which said spindle passes, outer and inner washers closely fitting said spindle for closing said perforations in the drum and for spacing said drum and brake-wheel, spring metal disks on said spindle bearing against the outer washers, and an adjustable lock-nut on said spindle for retaining all said parts in spaced frictional relation on said spindle.

7. A shock eliminator having in combina tion a supporting spindle rigidly mounted upon a bracket, a brake-wheel of box-like form mounted upon said spindle and rigidly secured thereto, a spiral spring within said wheel having its inner end connected to said spindle, a brake drum of box-like form having a tight fitting cover enclosing said brakewheel and springa pin projecting from one side of said drum for engaging the outer end of said spring, central perforations in the walls of said drum through which said spindle passes, said perforations being of enlarged diameter so that said drum will be capable of both rotary and radial movement with respect to said brake-wheel, outer and inner washers closely fitting said spindle for closing said perforations in the drum and for spacing said drum and brake-wheel spring metal disks on saidspindle bearing against the outer washers, and an adjustable lock-nut on said spindle for retaining all said parts in spaced frictional relation on said spindle.

8. A shock eliminator havingin combination a stationary supporting member, a brakewheel having a fixed position thereon, a brakedrunr surrounding said wheel and mounted upon said support soas to he capable of rotary and radial movement with respect to said wheel, a spiral spring connected between said support and drum, and

a pulling member having one end connected to said drum and its other end to a relatively stationary element.

9. A shock eliminator having in combination a stationary supporting member, a brakewheel havinga fixed position thereon, a spiral spring within said wheel having its inner end connected to said support, a brake-drum surrounding said wheel and to which the other end of said spring is connected, said drum being mounted upon said support so as to be capable of rotary and radialmovement with respect to said wheel, and a flexible pulling member wound'upon the periphery of said drum and having one end cletachably connected thereto and the other end adapted for adjustable connection to a relatively sta tionary element. 7

10. A shock absorber comprising an inner fixed drum, an outer drum mounted for radial movement with respect to the same, friction material between the drums, a spring within the drum, tending to turn one about the other,

a strap connected with the outer drum tend ing to turn it against the spring, in such amanner that as a pullis exerted on the strap the outer drum will be pressed towards one side of the inner drum causing resistance r to rotation, due to the friction material.

This specification signed at New York city, this 9th day of April, 1927.

EDWARD SLADE, 

